Justis, so you know Keynesian theory. But does it work?
Plenty of research to indicate that it is a pile of krud. And if it does work then how high a price does the taxpayer have to pay? For example, the stimulus packages that 'helped' our construction industry came at a cost of around $500,000 for every job 'saved'. A similar figure has been worked out for Obama's stimulus packages. Actually, on some research, the cost of a job 'saved' in the US was over $1.5M!
Your multiplier effect, if it works, unfortunately comes up against the Law of Diminishing Returns. E.g. every new stimulus needs to be more than the previous stimulus to get the same result as the previous one. Again research in the US has the multiplier effect around 20% so $1 spent by the government = 20c economic return. Not very efficient and all it does is leave a bigger debt that will need to be repaid at some stage.
And then you have the problem, and this is a biggie, that all the economic growth created by the stimulus is actually economic activity. It is a temporary sugar high with no lasting effect.
Even worse, it distorts the market and sends scarce resources to sectors that should not be receiving them. Instead those scarce resources to be going to sectors that have the real prospect of increasing economic growth.
I suggest you get yourself a broader understanding of economics and read up on the Austrian School of thought. It craps all over Keynesian.
